1. Field of the Invention
This invention relates generally to methods of delivering input signals from a remote control to a Java application. In particular, the present invention relates to methods of performing a process in response to remote control inputs provided to a device by forwarding the remote control inputs from the hardware and operating system software of the device to the Java application.
2. Description of the Related Art
Many modern devices rely in great part on real-time embedded software systems. Some of these devices operate in distributed communication environments in which they must be compatible with other devices and networks. As one example, cable boxes in cable television networks have become increasingly sophisticated and the current generation of cable boxes, now generally referred to as set-top boxes (STB) or digital entertainment terminals (DET), include advanced computer-like capabilities. See, for example, U.S. Pat. No. 5,635,979.
This convergence of video and computer technologies creates novel problems. For example, users of cable boxes are accustomed to using infrared remote control devices to perform simple television functions such as changing the channel, volume, etc. Moreover, they are accustomed to having their selected functions performed without delay. The modern compression and encryption techniques used in set-top boxes cause even relatively routine functions such as changing channels to require extensive processing, which in turn causes noticeable delays from the time the function is requested. See, for example, U.S. Pat. No. 5,477,263.
The problems of convergence are more exacerbated in more sophisticated set-top boxes. For example, in the integration of cable modems and internet access (i.e., web browser software) into set-top boxes and other devices, it is desired to support a host of related technologies such as the Intel Intercast™ technology for including internet data within the vertical blanking interval of a television signal and also the JavaScript™ scripting language for HTML.
Java™ is an especially attractive programming language when developing software applications because it is designed to enable the development of one “applet” which can run stand-alone in a variety of devices having different central processing units and operating system architectures. However, the present versions of Java™ available from Sun Microsystems or Microsoft is designed to receive input signals only from a standard computer keyboard and mouse. Java™ applets cannot directly receive input from an infrared remote control. While a Java™ applet could theoretically carry out repeated polling to ascertain the presence of remote control inputs, such a method can be problematic. There is always a maximum latency equal to the time delay between subsequent polls. If polling is carried out at a high frequency to reduce latency, there may be a large number of polling queries between actual remote control inputs. In a video-on-demand application where the user may not provide any inputs during the entire length of a movie, the resulting large number of polls may waste valuable processing resources. Thus, known polling methods are unsatisfactory for delivering remote control inputs to Java™ applications.